1. Field of the Invention
The field of the invention relates to surgical knife assemblies including depth guards for limiting the depth of incision of a cutting blade.
2. Brief Description of the Prior Art
It is important to control the depth of incision of a surgical knife blade during an operation. This is particularly important during eye surgery, and a number of devices having been developed for this particular application. U.S. Pat. Nos. 4,473,076, 4,499,898, 4,520,815 and 4,602,630 disclose various cutting instruments for use in eye surgery which include means for limiting the depth of incision of a surgical knife blade.
A conventional instrument known to the art comprises a footplate including a single plate or a pair of parallel plates separated from each other and defining a slot for receiving the knife blade. The footplate includes a flat bottom surface which rests upon the outer surface of the eye as an incision is made, thereby limiting the depth of incision of the blade. One of the problems with this conventional instrument is that the surgeon's field of view is obscured by the plates during the period the incision is made. This is especially true when surgery is performed using a microscope, as the surgeon will then attempt to view the incision from the side of the knife blade.